Electrical terminal with improved resilient biasing means

ABSTRACT

An improved electrical terminal of the type wherein the male portion of the terminal comprises a cylindrical prong and the female portion of the terminal comprises a mating cylindrical hole, the improvement going specifically to the manner in which the female portion and male portion are resiliently biased internally into snug mating contact with one another to ensure the reliable and uninterrupted transmission of electrical current therebetween. Specifically, the resilient biasing means preferably comprises a short bent wire captively contained within a longitudinal slot in the male prong.

United States Patent [191 Appleton Oct. 16, 1973 ELECTRICAL TERMINAL WITH IMPROVED RESILIENT BIASING MEANS [76] Inventor: Arthur I. Appleton, c/o Appleton Electric Company, 1701 W. Wellington, Chicago, Ill. 60657 22 Filed: 5 gigs; 197i 211 Appl. No.: 240,374

[52] US. Cl. 339/252 P [51] Int. Cl H01! 13/06 [58] Field Of Search 339/252, 256

[56] References Cited 7 UNITED STATES PATENTS 3,140,141 7/1964 Nava 339/256 R I 2,325,691 8/1943 Litwin et a] .L 339/256 R FOREIGN PATENTS OR APPLICATIONS 245,804 7/1947 Switzerland 339/252 P 704,456

3/1941 Germany 339/252 P Primary Examiner-Joseph H. McGlynn Attorney-Jon L. Liljequist [5 7] ABSTRACT An improved electrical terminal of the type wherein the male portion of the terminal comprises a cylindrical prong and the female portion of the terminal comprises a mating cylindrical hole, the improvement going specifically to the manner in which the female portion and male portion are resiliently biased internally into snug mating contact with one another to ensure the reliable and uninterrupted transmission of electrical current therebetween. Specifically, the resilient biasing means preferably comprises a short bent wire captively contained within a longitudinal slot in the male prong.

2 Claims, Drawing Figures ELECTRICAL TERMINAL WITH IMPROVED RESILIENT BIASING MEANS SUMMARY OF THE INVENTION This invention relates to a cylindrical terminal having preferably a longitudinal slot arranged therein along one side which contains a spring in the form of a slender bent wire. Preferably the male terminal is slotted and further has a hole drilled therein which receives one end of the spring member to positively locate it longitudinally of the prong, and the other end of the wire spring lies in the longitudinal slot and is captivated therein by a staking operation. Midportions of the spring extend slightly out of the slot to provide a resilient interference with the mating female portion of the terminal.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the male and female portions of the terminal, disengaged axially from one another, and embodying the present invention;

FIG. 2 is an enlarged cross-sectional view of the prong end portion of the male terminal showing details of construction with the spring biasing means in place;

FIG. 3 is a modified shape of the spring biasing means which may be used with the male prong; and

FIG. 4 is an inversion of the embodiment shown in the first three figures, that is, FIG. 4 shows a spring biasing means in the female portion of the improved terminal.

DESCRIPTION OF A PREFERRED EMBODIMENT The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of the patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

In the illustrated embodiment, there is shown the male portion of a terminal connection and. the female portion 12. The female portion includes a forward tubular end 14 and a rear end 16 adapted to be connected to a conductor such as the stranded wire 18. Specifically, the rear end 16 of the female is axially drilled to provide access for the conductor 18, and one sidewall is cross-drilled and tapped as at 22 so as to receive a setscrew 24. Setscrew 24 is tightened against the stranded wires to mechanically lock the wires to the terminal. These details of the female portion 12 have been practiced for many years and form no part of the present invention.

Referring now to the male portion 10 of the terminal, this portion includes a forward prong end 26 of generally cylindrical configuration, an intermediate cylindrical extension portion 28 of larger diameter than forward end 26, and a rear end 30. Rear end 30 of the male portion 10 is essentially identical to the rear end 16 of the female portion 12, and it includes a drilled hole 32 extending axially into its rearmost end, a crossdrilled and tapped hole 34, and a setscrew 36 for locking the stranded wires of a conductor 38 in the drilled hole 32. Again, this general overall description of the male portion 10 is of well known design.

Referring now specifically to forward prong end 26 of the male portion 10, this end includes slot means 40 running generally longitudinally thereof. Slot 40 is relatively thin and extends radially into the prong end and to a depth preferably less than half way so as not to appreciably diminish the current carrying capacity of the prong end.

Near the forwardmost end of the prong and extending transversely radially inward from a starting point at the base of slot 40 is a cross-drilled hole 42. Crossdrilled hole 42 serves to contain and locate one end 50 of biasing means, generally 52, in the form preferably of a performed piece of spring wire of generally L shape. The other end 54 of spring 52 extends rearwardly and lays within the groove 40. Slightly forwardly of end 54 are means for securing the spring in place, and herein these means take the form of prong material staked inwardly to retain this end of the biasing means within slot 40.

Midportions 56 of the biasing means 52 curve so as to jut outwardly slightly beyond the outer extremities of slot 40. The amount portions 56 jut outwardly is adjusted to ensure that it will interferingly engage the inner diameter of forward tubular end 14 of the female portion 12 of the terminal when the two are matingly engaged. Because cross-drilled hole 42 is slightly larger in diameter than the wire diameter forming biasing means 52, and because the staking 44 only loosely captivates end 54 of the biasing means 52, biasing means 52 is somewhat free to resiliently move in its captive slot 40, although the extent of this movement is not apparently appreciable. Thus, when prong end 26 is inserted in tubular end 14 of the female portion, biasing means 52 is compressed somewhat, but its inherent resiliency maintains a desirable pressure between the prong side opposite the spring and the inner wall of the female inner wall.

FIG. 3 shows an alternate shape for biasing means 52 which is preformed with an additional bend 60 beyond that of the preformed wire shown in FIG. 2, and this bend 60 causes a desirable feel to the connection when inserted and withdrawn.

It will be understood that there can be considerable variationsin the specific shape shown without departing from the spirit of this invention. Merely by way of example, cross-drilled hole 42 might rather be a longitudinal hole eminating at the forwardmost portion of the prong tip.

In this case, the spring means 52 would begenerally J shaped. Similarly, the prong might be slotted on diametrically opposite sides with a U shaped biasing means fitted with a different leg in each slot.

Referring now specifically to FIG. 4, it will be noted that the same philosophy applied to the male portion as described in the earlier material can be applied to the female portion of the terminal. In this figure, a tubular female terminal includes a longitudinal slot 72 which breaks entirely through the sidewall at only the center portion 74 of the slot. A preformed spring 76includes opposite ends 78 and 80 which lie in slot 72 and are constrained therein by means of staking such as at 82 and 84. Midportions 86 of the spring 76 are bent downwardly so as to extend through the breakthrough opening 74 and jut radially and interferringlyinto the inner diameter of the female tubular terminal 70. As

will be understood, when a male cylindrical terminal is inserted into the female tubular terminal 70, spring 76 will bear thereagainst and hold the two in snug engagement.

I claim:

1. In an electrical terminal including a male portion having a cylindrically shaped insertion end for use in conjunction with the mating female portion having a cylindrical hole of a diameter slightly larger than said insertion end into which the insertion end is inserted to make an electrical connection, said insertion end including a slot with a spring member therein which juts partially out of said slot to engage the inner sidewall of the female portion and maintain a good electrical connection between the male portion and the female portion, the improvement comprising:

said insertion end being defined in part by a hole extending transversely thereof and adjacent its forwardmost extremities, said hole initiating at the base of said slot;

said spring member having one major bend therein forming said spring member into generally an L shape of which one end is disposed within said transverse hole, the remainder of the spring member curving rearwardly therefrom in said slot to the other end,

and means for positively holding said spring in said slot, said means partially closing said slot over a portion of said spring member to thereby prevent its free removal.

2. The improvement as defined in claim 1, wherein said L shaped spring member has a long leg and a short leg, said long leg comprising said remainder of the spring member and including an additional but lesser bend than said major bend to provide extended engagement between said spring member and said female portion. 

1. In an electrical terminal including a male portion having a cylindrically shaped insertion end for use in conjunction with the mating female portion having a cylindrical hOle of a diameter slightly larger than said insertion end into which the insertion end is inserted to make an electrical connection, said insertion end including a slot with a spring member therein which juts partially out of said slot to engage the inner sidewall of the female portion and maintain a good electrical connection between the male portion and the female portion, the improvement comprising: said insertion end being defined in part by a hole extending transversely thereof and adjacent its forwardmost extremities, said hole initiating at the base of said slot; said spring member having one major bend therein forming said spring member into generally an L shape of which one end is disposed within said transverse hole, the remainder of the spring member curving rearwardly therefrom in said slot to the other end, and means for positively holding said spring in said slot, said means partially closing said slot over a portion of said spring member to thereby prevent its free removal.
 2. The improvement as defined in claim 1, wherein said L shaped spring member has a long leg and a short leg, said long leg comprising said remainder of the spring member and including an additional but lesser bend than said major bend to provide extended engagement between said spring member and said female portion. 